1. Field of the Invention
The present invention relates to device and method for detecting defect in an air conditioner, and more particularly, device and method for detecting anomaly of an air conditioner by using the acoustic emission method.
2. Background of the Related Art
The air conditioner, maintaining a room temperature at a desired level, has a refrigerant compressor essentially required for compression of the refrigerant in conversion of a phase of the refrigerant. What gives the most fatal influence to an anomaly of the air conditioner in whole is the compressor. FIG. 1 illustrates a related art outdoor unit of an air conditioner.
Referring to FIG. 1, there is a compressor 100 mounted on a base plate 18 between a front casing and a rear casing 10 and 12 of the outdoor unit. The refrigerant compressed in such a compressor is passed through a phase change as the refrigerant discharges a heat at a heat exchanger 14, and supplied to an indoor unit(not shown).
A system of the related art compressor 100 in an air conditioner will be explained with reference to FIGS. 2 and 3. As shown, the compressor 100 is provided with a case 101 having a built in mechanism for compressing the refrigerant, and an accumulator 103 for supplying the refrigerant into the compressor. Within the case 101, there is a motor 102 for generating a power for compressing the refrigerant and a compression part for compressing the refrigerant by using the power generated at the motor. The compression part has a cylinder 105 with a suction hole 104, and a compression chamber 108 between an upper and lower bearings 106 and 107. In the compression chamber 108, there is an eccentric shaft 109 rotatably fixed in the compression chamber 108 as shown in FIG. 3. And, on the eccentric shaft 109, there is a rolling piston 110 mounted thereon for making continuous contact to an inside surface of the compression chamber 108.
In such a system, when the power is applied to the compressor, the motor 102 in the case 101 comes into operation, to rotate the eccentric shaft 109, when the rolling piston 110 rotates along an inside wall of the compression chamber 108, to an outside diameter of which rolling piston 110 a vane 111 elastically fitted in the cylinder 105 by a spring 112 is brought into contact periodically, to draw the refrigerant from the accumulator 103 into the compression chamber 108 through the suction hole 104 in the cylinder 105. The refrigerant drawn thus is compressed as the rolling piston 110 rotates, and discharged to outside of the compressor through an outlet. Being an important part a basic performance of a refrigerating cycle relies thereon, a defective compressor gives a fatal influence to entire air conditioner. And, this influence gives a fatal influence to defects of entire air conditioner actually, an inspection of the compressor itself is very important. Since the detect in the compressor itself directly affects to the detect in the air conditioner itself actually, the detect in the compressor is a criterion for determining a detect in the air conditioner. However, determination of the defect in the compressor itself only from mechanism by an outer appearance is not easy. And, what is important is determination of detect in the air conditioner itself actually, it is a right approach in determination of the detect in the air conditioner that the determination of defect is only made in a state the compressor is assembled to complete an air conditioner.
A related art method for determining a detect in a completed air conditioner on the whole will be reviewed, briefly. The most primary established method is to determine the defect an air conditioner from noise and vibration relying on auditory and visual senses of a skilled worker after putting a completed air conditioner into a rated power operation on an air conditioner production line. However, since this sense based method is influenced from an environment of the production line and the inspector's subjective view, reliability of the method can not be assured, fully. And, because of the problem of this sense based determination method, a method is widely used, in which an operational current is sensed by using a sensing device on a transfer line of the air conditioner, and the detect in the air conditioner is determined based on the sensed current.
However, this current sensing method has disadvantage in that a right determination of the air conditioner is impossible in cases of abnormal wear and the like of components coming from unbalance of materials, machining error and/or assembly error, or the like of components because the current sensing method is based on currents for general factors, such as low compression, reverse discharge, electronic noise, abnormal noise, low input, and the like of the compressor in case of two phases. For example, a right determination of detect in the air conditioner is not possible in cases the defect comes from a machining or assembly error of various components in the compressor. To cope with this, the inventor discloses a patent in Korean Patent publication No. 192251 dated Jun. 15, '99 in which a method for determining anomaly of a compressor by using an acoustic emission method is suggested. However, since this method has a precondition of driving, not the air conditioner itself, but the compressor only, this method is less effective in determining detect in the whole air conditioner having the compressor assembled thereto.